/Engine/Plugins/Developer/Concert/ConcertMain/Source/ConcertTransport/Public/IConcertEndpoint.h
Add an Event Handler
virtual void InternalAddEventHandler ( const [FName](API\Runtime\Core\UObject\FName) & EventMessageType, const [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [IConcertEventHandler](API\Plugins\ConcertTransport\IConcertEventHandler) > & Handler )